DEFICIENT, ADEQUATE AND EXCESS NITROGEN LEVELS ESTABLISHED IN HYDROPONICS FOR BIOTIC AND ABIOTIC STRESS-INTERACTION STUDIES IN POTATO

摘要

Application of mineral nutrients to improve plant health is critical to providing food and fiber. Potato (Solanum tuberosum L.) is among the most responsive species to N application but is susceptible to biotic and abiotic stresses. Nitrogen-stress relationships are generally evaluated indirectly during field fertility trials designed for collection of agronomic data. A controlled environment system would benefit understanding N nutrition-stress interactions. Environmental chamber hydroponics allows strict experimental control of temperature, humidity, light, etc. while maintaining specific N nutrition. Potatoes were grown at various N levels. Plant biomass had a curvilinear relationship with N supply, peaking at 80 mg N L-1. Root or shoot N regressed against solution N produced significant, predictable relationships (R-2 0.98 for each). Such relationships provide a basis to conduct controlled N nutrition-abiotic-biotic stress studies that could delineate among stress factors. This work establishes the specific ranges of N needed to complete such research.